Trace elements important in the medical, nutritional or food science field are 16 elements including sodium, potassium, chlorine, calcium, magnesium, phosphorus and sulfur which are regarded as major minerals, and iron, zinc, copper, manganese, cobalt, chromium, iodine, molybdenum and selenium. These minerals are called essential metals or essential minerals. In spite that their intake amount is trace, they are indispensable elements and must be provided from outside of the body. The National Nutrition Survey 1998 in Japan (“Present Status of National Nutrition in 1998”, Ministry of Health, Labor and Welfare), however, expressed misgivings about insufficient iron intake of young women, in addition to insufficiency of calcium intake which has been said for these days.
Minerals have an important function in the living body and when they are deficient, a deficiency disease inherent to deficiency of each of them occurs. For example, iron is effective for qualitative improvement of blood, formation of erythrocytes, stress control, prevention of infectious diseases, increase in the strength of mucous membrane, reinforcement of connective tissue, improvement of immunity, enhancement of resistance to diseases, growth promotion, metabolism promotion of Vitamin B group, improvement of oxygen circulation, activation of brain cells and production of energy. Examples of the symptoms which may occur when iron is insufficient include swelling, incomplete development, wake in a bad temper, cartilage deformity, eczema, hypodynamia, drying of mucous membrane, dizziness, stiffness in the shoulder, reduced vigilance, weakened immunity, shortness of breath, paleness of the skin, getting tired easily, excessive sensitivity to cold, dizziness on standing up, palpitation, low sexual desire, blood from the gums, weakening of connective tissue, hair loss, loss of appetite, nervousness, gait disturbance, angular cheilitis, stomatitis, cheilitis, headache, anemia and noise in the ears.
Zinc is effective for digestion of carbohydrates, synthesis of proteins, assistance in the metabolism of Vitamin B1 or proteins, growth and maturation of sex organs, synthesis of insulin, improvement of the brain function, promotion of wound healing, regulation of Vitamin A metabolism and formation of bones. Examples of the symptoms which may occur when zinc is insufficient include underdevelopment, excessive sensitivity to cold, low wound-healing power, impaired leaning ability, weakening of sexual function, gustatory or olfactory sense disorder, enlarged prostate, arteriosclerosis, accumulation of cholesterol, lowering in resistivity against infections, hair loss, gout, leukemia, cancer, induction of cardiac diseases, diabetes, and pigmented spots.
Calcium serves to form bones and teeth, maintain the cardiac function, cause muscle contraction, relax hypersensitivity, stress or menstrual pain, promote blood clotting, adjust water content in the body, and improve ovulation function. Examples of the symptoms which may appear when calcium is insufficient include osteomalacia, osteoporosis, underdeveloped teeth growth., rickets, palpitation, insomnia, neurosis, arthritis, hypertension, arteriosclerosis, insufficient blood clotting, asthma and nasal allergy.
Magnesium serves to regulate intracellular osmotic pressure, adjust the acid-alkali balance, enhance absorption of Vitamin A group, B group, C, D and E and calcium, prevent deposition of cholesterol, relax mental stress, provide a fine skin, treat nephrolith, prevent diabetes, and prevent alcoholic poisoning. Examples of the symptoms which may occur when magnesium is insufficient include underdevelopment, excessive hypersensitivity, muscle stiffness, convulsion, angina pectoris, myocardial infarction, renal failure, bad complexion, arteriosclerosis, thrombosis, seizure, leukemia and cancer.
At present, deficient minerals are made up for by the administration of tablets, granules or liquids containing the minerals between or after meals. It is however reported that absorption of some of these minerals, for example, iron absorption, is disturbed by catechin contained in a green tea or herb, chlorogenic acid in coffee, or polyphenol in cocoa or wine (Brune M, Rossander L, Hallberg L, “Iron absorption and phenolic compounds: Importance of different phenolic structures”, European Journal of Clinic and Nutrition, Vol. 43, 547–558(1989)). It is also reported that coffee disturbs not only the absorption of iron but also that of zinc (Coudray C, Bousset C, Tressol J. Pepin D, Rayssiguire Y, “Short-term ingestion of chlorogenic or caffeic acids decreases zinc but not copper absorption in rats, utilization of stable isotopes and inductively-coupled plasma mass spectrometry technique.”, British Journal of Nutrition, vol. 80, 575–584 (1998)). Patients supplemented with iron preparations have been instructed for years not to take beverages such as tea or coffee. (Maro Ishibashi, Toshiro Motoya, “Zusetsu Kusuri no Tainai Dotai (13)”, Yakkyoku, Vol. 39, 113–117 (1988).
With popularization of PET-bottled beverages or canned beverages in recent years, tea and coffee have been preferred widely by all age groups. In consideration that there is a fear of young women suffering from iron deficiency as described above, mineral deficiency is a problem to be overcome as soon as possible.